Bicycle Mechanics - Need a new BB?

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eliktronik
08-17-04, 09:58 PM
Hey everyone, I've noticed that the BB on my road bike, which I believe is an older Schwinn, has some play to it. The axle (wrong term?) that the cranks anchor to wobbles around. Every fastener that I can see is tight. Does this mean I need a new BB? And, most importantly, how do I go about finding the right replacement? I'm looking to buy something cheap, most likely used on ebay. What should I measure/check on mine to make sure I'm buying the right part? Basically any info would be helpful. Thanks in advance, these are really great forums!
:beer:
I'd suggest replacing it. Bottom brackets have become reasonably cheap.
I definitely wouldn't get one off ebay.
You can get these Shimano ones, which are "105" level for about $21:
http://harriscyclery.net/site/itemdetails.cfm?ID=1203
And there are cheaper ones.
Hey everyone, I've noticed that the BB on my road bike, which I believe is an older Schwinn, has some play to it. The axle (wrong term?) that the cranks anchor to wobbles around. Every fastener that I can see is tight. Does this mean I need a new BB? And, most importantly, how do I go about finding the right replacement? I'm looking to buy something cheap, most likely used on ebay. What should I measure/check on mine to make sure I'm buying the right part? Basically any info would be helpful. Thanks in advance, these are really great forums!
:beer:You have to match the BB to the crank and also the frame threading. You aslo have to have tools and knowledge.Easier and cheaper to take it to a bike shop.
Chances are that you have a cup and cone style BB. What has probably happened is one or both cups that thread into the BB shell have come loose. If you look at the left side of the BB shell you should be able to see a silver lockring that fixes the adjustment in place.
You most likely do not need a new BB. The old style BBs are pretty tough. What you do need to do (or have done) is to remove the cranks and the BB, clean, grease, reinstall, and adjust. If you have the tools, it's an easy job, similar to repacking wheel bearings. You need a crank puller, a lockring spanner, and a pin wrench to do it yourself. As suggested by sydney, you may want to have an LBS do it for you.
If you have a newer sealed BB, then any play in the spindle indicates the BB is shot and must be replaced. Replacement requires a crank puller and a BB tool that matches your BB. If you need a new one, the best thing is to take it to an LBS to get the right size. You need to measure the width of the spindle and get a new BB with the same threads and width. A new BB is pretty cheap and I would not bother with buying something used.
eliktronik
08-18-04, 02:51 PM
Chances are that you have a cup and cone style BB. What has probably happened is one or both cups that thread into the BB shell have come loose. If you look at the left side of the BB shell you should be able to see a silver lockring that fixes the adjustment in place.
....
Thank you very much for the info. I'd much rather buy the tools and repair it myself that pay more than the bike is worth for service...
I believe you are right about the style of BB I have. So basically, once I pull the cranks off, I should be able to take that ring off to remove the BB? Thanks again.
Yes. when you pull the BB spindle out, there should be a plastic tube that fits around the spindle. Be sure to replace it when you reassemble. It protects the bearings from junk that falls down to the BB shell.
You'll probably spend more on tools than a LBS will charge but afterward you get to keep the tools for the next time.
Yes. when you pull the BB spindle out, there should be a plastic tube that fits around the spindle. Better term is 'may be a protective sleeve'. Seen more that didn't have it than did.
eliktronik
09-15-04, 06:30 PM
I'd like to thank everyone again for the info. I finally got around to repacking the bearings and adjusting the BB today. All in all it was pretty easy after reading Sheldon Brown's site. I'm one step closer towards mastering bike repair now ;)
Next time you repack your BB, replace the balls themselves, as they tend to elongate with use. If your ball bearings came in plastic or metal retainers, convert to loose balls, which will extend the life of your spindle and cups. Also, retorque your crank bolts after about 50 miles / 75 km.
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